Discrete Conditional Phase-type Model Utilising a Multiclass Support Vector Machine for the Prediction of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a rare disease in which retinal blood vessels of premature infants fail to develop normally, and is one of the major causes of childhood blindness throughout the world. The Discrete Conditional Phase-type (DC-Ph) model consists of two components, the conditional component measuring the inter-relationships between covariates and the survival component which models the survival distribution using a Coxian phase-type distribution. This paper expands the DC-Ph models by introducing a support vector machine (SVM), in the role of the conditional component. The SVM is capable of classifying multiple outcomes and is used to identify the infant's risk of developing ROP. Class imbalance makes predicting rare events difficult. A new class decomposition technique, which deals with the problem of multiclass imbalance, is introduced. Based on the SVM classification, the length of stay in the neonatal ward is modelled using a 5, 8 or 9 phase Coxian distribution.

Treatment of retinopathy of prematurity in Northern Ireland, 2000-2011: a population-based study

Purpose To evaluate the incidence of treatment-requiring retinopathy of prematurity (ROP) over a 12-year-period in Northern Ireland. Methods The medical records of all infants treated for ROP from January 2000 to December 2011were retrospectively reviewed and cross-referenced with the Neonatal Intensive Care Outcomes Research and Evaluation (NICORE) database. Results The Northern Ireland population data showed an increase in the number of live births from 2000 to 2011. The proportion of babies born with a birth weight <1501 g and/or <32 weeks’ gestational age remained constant (χ2 trend = 3.220, P = 0.0727), although the proportion of these babies who died prior to 42 weeks’ gestation decreased from 2000 to 2011 (P = 0.0196 using χ2 for trend = 5.445; P = 0.0354 using χ2 = 20.809). The prevalence of treatment-requiring ROP in these infants increased from 1.05% in 2000 to 5.78% in 2011 (P < 0.001 using χ2 trend = 16.309; P < 0.001 using χ2 = 31.378). Conclusions The present population-based study highlights that the incidence of treatment- requiring ROP is increasing in Northern Ireland. The increasing number of infants requiring treatment will need to be taken into consideration in the commissioning process for ROP services in Northern Ireland.

An R-matrix approach for plasma modelling and the interpretation of astrophysical observation

Over the last decade an Auburn-Rollins-Strathclyde consortium has developed several suites of parallel R-matrix codes [1, 2, 3] that can meet the fundamental data needs required for the interpretation of astrophysical observation and/or plasma experiments. Traditionally our collisional work on light fusion-related atoms has been focused towards spectroscopy and impurity transport for magnetically confined fusion devices. Our approach has been to provide a comprehensive data set for the excitation/ionization for every ion stage of a particular element. As we progress towards a burning fusion plasma, there is a demand for the collisional processes involving tungsten, which has required a revitalization of the relativistic R-matrix approach. The implementation of these codes on massively parallel supercomputers has facilitated the progression to models involving thousands of levels in the close-coupling expansion required by the open d and f sub-shell systems of mid Z tungsten. This work also complements the electron-impact excitation of Fe-Peak elements required by astrophysics, in particular the near neutral species, which offer similar atomic structure challenges. Although electron-impact excitation work is our primary focus in terms of fusion application, the single photon photoionisation codes are also being developed in tandem, and benefit greatly from this ongoing work.

Complicações músculo-esqueléticas crónicas nas mulheres sobreviventes de cancro da mama

As mulheres com cancro da mama obtiveram, nos últimos anos, um aumento significativo da esperança média de vida; contudo, muitas destas mulheres vivem com as complicações crónicas resultantes do tratamento. O objetivo deste estudo é caracterizar as complicações músculo-esqueléticas (CME) nas sobreviventes de cancro da mama e enfatizar a necessidade de desenvolver terapêuticas preventivas para estas complicações. Métodos – Noventa e quatro mulheres sobreviventes de cancro da mama responderam a um questionário sobre potenciais CME. Resultados – Foi detetada associação significativa entre idade e linfedema (p=0,004), dor no braço (DB) (p=0,000), dor no ombro (DO) (p=0,004), dificuldade em elevar o braço (DEB) (p=0,022) e cervicalgia (p=0,000), verificando-se uma maior incidência nas mulheres com mais de 50 anos. Uma associação significativa foi detetada entre linfadenectomia e linfedema (p=0,000), DB (p=0,000), DO (p=0,008), verificando-se que as mulheres sujeitas a linfadenectomia apresentam maior incidência de linfedema, de DB e de DO. Quanto à sobrevivência constatou-se que as mulheres com mais de 10 anos de sobrevivência têm mais CME. Relativamente à mastectomia foi detetada associação significativa com o linfedema (p=0,012), DB (p=0,020), DO (p=0,003), DEB (p=0,037) e cervicalgia (p=0,020). Verificou-se que as mulheres mastectomizadas têm maior tendência para apresentar linfedema, DB, DO, DEB e cervicalgia. Conclusão – No nosso estudo, as mulheres acima dos 50 anos, as que realizaram a linfadenectomia, as com mais de 10 anos de sobrevivência e as mastectomizadas apresentaram maior incidência de CME.

Study on period search methods of variable stars: Application to ASAS and CRTS databases

Study on variable stars is an important topic of modern astrophysics. After the invention of powerful telescopes and high resolving powered CCD’s, the variable star data is accumulating in the order of peta-bytes. The huge amount of data need lot of automated methods as well as human experts. This thesis is devoted to the data analysis on variable star’s astronomical time series data and hence belong to the inter-disciplinary topic, Astrostatistics. For an observer on earth, stars that have a change in apparent brightness over time are called variable stars. The variation in brightness may be regular (periodic), quasi periodic (semi-periodic) or irregular manner (aperiodic) and are caused by various reasons. In some cases, the variation is due to some internal thermo-nuclear processes, which are generally known as intrinsic vari- ables and in some other cases, it is due to some external processes, like eclipse or rotation, which are known as extrinsic variables. Intrinsic variables can be further grouped into pulsating variables, eruptive variables and flare stars. Extrinsic variables are grouped into eclipsing binary stars and chromospheri- cal stars. Pulsating variables can again classified into Cepheid, RR Lyrae, RV Tauri, Delta Scuti, Mira etc. The eruptive or cataclysmic variables are novae, supernovae, etc., which rarely occurs and are not periodic phenomena. Most of the other variations are periodic in nature. Variable stars can be observed through many ways such as photometry, spectrophotometry and spectroscopy. The sequence of photometric observa- xiv tions on variable stars produces time series data, which contains time, magni- tude and error. The plot between variable star’s apparent magnitude and time are known as light curve. If the time series data is folded on a period, the plot between apparent magnitude and phase is known as phased light curve. The unique shape of phased light curve is a characteristic of each type of variable star. One way to identify the type of variable star and to classify them is by visually looking at the phased light curve by an expert. For last several years, automated algorithms are used to classify a group of variable stars, with the help of computers. Research on variable stars can be divided into different stages like observa- tion, data reduction, data analysis, modeling and classification. The modeling on variable stars helps to determine the short-term and long-term behaviour and to construct theoretical models (for eg:- Wilson-Devinney model for eclips- ing binaries) and to derive stellar properties like mass, radius, luminosity, tem- perature, internal and external structure, chemical composition and evolution. The classification requires the determination of the basic parameters like pe- riod, amplitude and phase and also some other derived parameters. Out of these, period is the most important parameter since the wrong periods can lead to sparse light curves and misleading information. Time series analysis is a method of applying mathematical and statistical tests to data, to quantify the variation, understand the nature of time-varying phenomena, to gain physical understanding of the system and to predict future behavior of the system. Astronomical time series usually suffer from unevenly spaced time instants, varying error conditions and possibility of big gaps. This is due to daily varying daylight and the weather conditions for ground based observations and observations from space may suffer from the impact of cosmic ray particles. Many large scale astronomical surveys such as MACHO, OGLE, EROS, xv ROTSE, PLANET, Hipparcos, MISAO, NSVS, ASAS, Pan-STARRS, Ke- pler,ESA, Gaia, LSST, CRTS provide variable star’s time series data, even though their primary intention is not variable star observation. Center for Astrostatistics, Pennsylvania State University is established to help the astro- nomical community with the aid of statistical tools for harvesting and analysing archival data. Most of these surveys releases the data to the public for further analysis. There exist many period search algorithms through astronomical time se- ries analysis, which can be classified into parametric (assume some underlying distribution for data) and non-parametric (do not assume any statistical model like Gaussian etc.,) methods. Many of the parametric methods are based on variations of discrete Fourier transforms like Generalised Lomb-Scargle peri- odogram (GLSP) by Zechmeister(2009), Significant Spectrum (SigSpec) by Reegen(2007) etc. Non-parametric methods include Phase Dispersion Minimi- sation (PDM) by Stellingwerf(1978) and Cubic spline method by Akerlof(1994) etc. Even though most of the methods can be brought under automation, any of the method stated above could not fully recover the true periods. The wrong detection of period can be due to several reasons such as power leakage to other frequencies which is due to finite total interval, finite sampling interval and finite amount of data. Another problem is aliasing, which is due to the influence of regular sampling. Also spurious periods appear due to long gaps and power flow to harmonic frequencies is an inherent problem of Fourier methods. Hence obtaining the exact period of variable star from it’s time series data is still a difficult problem, in case of huge databases, when subjected to automation. As Matthew Templeton, AAVSO, states “Variable star data analysis is not always straightforward; large-scale, automated analysis design is non-trivial”. Derekas et al. 2007, Deb et.al. 2010 states “The processing of xvi huge amount of data in these databases is quite challenging, even when looking at seemingly small issues such as period determination and classification”. It will be beneficial for the variable star astronomical community, if basic parameters, such as period, amplitude and phase are obtained more accurately, when huge time series databases are subjected to automation. In the present thesis work, the theories of four popular period search methods are studied, the strength and weakness of these methods are evaluated by applying it on two survey databases and finally a modified form of cubic spline method is intro- duced to confirm the exact period of variable star. For the classification of new variable stars discovered and entering them in the “General Catalogue of Vari- able Stars” or other databases like “Variable Star Index“, the characteristics of the variability has to be quantified in term of variable star parameters.

Dimensionalizaci??n del constructo de ocio en universitarios

Resumen en ingl??s y castellano

Valoraci??n de la gravedad de las situaciones de desprotecci??n infantil por los profesionales de los servicios de protecci??n infantil

Resumen tomado de la publicaci??n

Errores en la escritura de s??labas con grupos conson??nticos de s??labas : un estudio transversal

Resumen de ingl??s y castellano

Measure of the ability to rotate mental images

Resumen tomado de la publicaci??n

Control contextual en el aprendizaje de n??meros para un ni??o con discapacidad intelectual

Resumen tomado de la publicaci??n

Global and dominance with concentric hierarchical stimuli and orientation classification task. 'Dominancia global y local con est??mulos conc??ntricos y tareas de clasificaci??n de la orientaci??n'

Resumen tomado de la publicaci??n. Resumen tambi??n en ingl??s

Gender activation in transparent and opaque words

Resumen tomado de la publicaci??n

Diferencias entre expertos y noveles en las estimaciones sobre el poder predictivo de las claves en el ??mbito de la delincuencia

Resumen tomado de la publicaci??n

Sesgos cognitivos en el reconocimiento de expresiones emocionales de voz sint??tica en la alexitimia

Resumen tomado de la publicaci??n

Estrategias de b??squeda y utilizaci??n de la informaci??n en trabajos acad??micos en educaci??n superior

En el proceso de adaptaci??n de los nuevos Planes de Estudio al Espacio Europeo de la Educaci??n Superior, una de las competencias gen??ricas que se consideran fundamentales en todas las titulaciones es la denominada 'Gesti??n de la Informaci??n'. Se exponen las caracter??sticas de un proyecto de innovaci??n que pretende favorecer el desarrollo de esta competencia en el proceso de ense??anza-aprendizaje de varias asignaturas de la titulaci??n de Pedagog??a de la Universidad de Oviedo. Se presenta el desarrollo de una experiencia, enmarcada en dicho proyecto, realizada en la asignatura optativa 'Integraci??n social de personas con discapacidad'. La actividad propuesta se realiz?? en grupos de tres o cuatro alumnos y consisti?? en que cada alumno analizara las distintas alternativas laborales existentes para las personas con discapacidad e identificara la m??s id??nea para cada caso particular. Se trat?? de comprobar el dominio de algunas de las habilidades incluidas en la 'Gesti??n de la Informaci??n' como la eficacia del proceso de b??squeda de informaci??n y la presentaci??n de fuentes referenciales en los trabajos acad??micos del alumnado. El proyecto se desarroll?? en tres fases: la primera, consisti?? en una revisi??n de las herramientas y estrategias de b??squeda de informaci??n contenidas en los proyectos previos y en la realizaci??n de b??squedas individuales para localizar documentos pertinentes para realizar el trabajo planteado; en la segunda fase, los alumnos deb??an valorar los documentos localizados, atendiendo a los criterios de autor??a, actualizaci??n, fiabilidad de la fuente y utilidad, y, seleccionar aquellos m??s interesantes para la realizaci??n de su trabajo escrito; en la tercera y ??ltima fase, cada grupo ha elaborado un trabajo escrito utilizando los documentos seleccionados en la fase anterior. Se concluye, que el alumnado universitario presenta claras deficiencias en cuanto al conocimiento y manejo de las herramientas de b??squeda documental -preferencia por el uso de buscadores generalistas en lugar de herramientas m??s especializadas, falta de pr??ctica en las opciones avanzadas de las herramientas utilizadas, etc.-, y que, adem??s, es frecuente el uso de expresiones y textos de otros autores como propios. Por lo que se considera necesario, que la formaci??n en esta competencia se realice desde los cursos iniciales de las distintas titulaciones y se fomente su uso en distintas asignaturas.